Meet Longhorn: Cloud-Native Distributed Block Storage for Kubernetes

Why Longhorn for Kubernetes Stateful Workloads?

Longhorn is a lightweight, reliable, and CNCF-graduated distributed block storage system for Kubernetes. It partitions block storage into isolated Longhorn Engine and Replica instances using container and microservice primitives, replicating every PersistentVolume across multiple worker nodes.

Prerequisites & Node Preparation

Ensure open-iscsi and nfs-common are installed and active across all Kubernetes worker nodes:

sudo apt-get update && sudo apt-get install -y open-iscsi nfs-common
sudo systemctl enable --now iscsid

Installing Longhorn via Helm

helm repo add longhorn https://charts.longhorn.io
helm repo update

helm install longhorn longhorn/longhorn \
  --namespace longhorn-system \
  --create-namespace \
  --set defaultSettings.defaultReplicaCount=3

Validating Dynamic Provisioning

Once kubectl get sc shows longhorn (default), any PersistentVolumeClaim automatically provisions a 3-replica block volume across distinct worker nodes, ensuring zero data loss if a worker host fails.